there are 2 versions of the iXpand and they both use different apps. Make sure you are using the correct app.
If you have the version 1 SDIX-XXX then you may need to update the FW using a PC. Here is a link with instructions http://kb.sandisk.com/app/answers/detail/a_id/17496/
If you are still having issues you may need to contact sandisk support
